With the use of a seed washing technique, more than 4000 Gram negative bacteria were isolated
by two improved isolation methods from 446 batches of 1 kg rice seed samples obtained from 22 provinces in
the Philippines. They were initially characterized on the basis of colony morphology and results of biochemical
and pathogenicity tests. Six hundred and fifty-two strains were further identified by Biolog, from which 133
were selected for fatty acid methyl ester (FAME) analysis together with 80 standard reference! strains. Sixteen
species or types of Pseudomonas and 17 genera of non-pseudomonads were identified, more than one third
of which have not been recorded in rice. The most predominant species observed were P. putida and P. fulva.
About 17% of the strains of Pseudomonas and 2% of the non-pseudomonads were antagonistic to one or
more fungal or bacterial pathogens of rice. Rice seed is an important source of biological control agents.